1. Field of the Invention
The present invention relates generally to expansion devices and, more specifically, to expansion devices having a fixed orifice.
2. Description of Related Art
Certain refrigerant units, specifically, smaller units and multiple evaporator units (commonly referred to as xe2x80x9cmulti-vapsxe2x80x9d) typically use smaller orifices than larger units. Many of the available fixed orifice devices available are as large as the service valves themselves on these units. Most of them require a custom enclosure of some sort, some of them are pressed in, and others are brazed in.
The present invention includes a device designed to work with a standard ARI (American Refrigeration Institute) xc2xcxe2x80x3 flare fitting, already present on most service valves. In use, a service valve manufacturer may add another flare fitting in place of the outlet port on the service valve to avail himself of the advantages of a device according to the present invention. This device permits balancing the system by simply removing one orifice size and substituting another with a simple valve core removal tool as opposed to torch welding or pressing another orifice device into the system. In addition, as many as four orifices in one service valve package may be used to feed four evaporators connected to one condensing unit, without adding any additional bulk to the package other than the four xc2xcxe2x80x3 flare ports required to hold the orifices.
In one example, multi-vaps commonly use manifolds connected to tubes containing fixed orifices, one per circuit. Using one service valve with 2, 3, or 4 devices according to the present invention eliminates the manifold and 2, 3, or 4 tube/orifice combinations from the mass and volume of the total unit. If different size evaporators are used, such devices may be easily changed out to balance the system, whereas manifold-tube combination would require unbrazing the assembly to change the orifice size. Thus, a device according to the present invention represents an economical substitute, especially in custom installations.
In one embodiment, the present invention includes a refrigerant coupling having a body with first and second ends, an orifice extending therethrough for flow of a desired fluid, in which the first end has an externally threaded portion, and the second end has a sealing member. Further, the coupling includes a refrigeration port having first and second ends and a bore extending therethrough, in which one end has an internally threaded portion, and the other end has a connecting member. The port is sized to receive the body; and when the externally threaded portion of the body is engaged within the bore, the sealing member is in sealing relation to the bore.
In another embodiment, the present invention includes a fixed orifice expansion device with a body having first and second ends, means for torquing the body into a desired location of a cooperative port, and a sealing member. Further, the body has an orifice extending therethrough for conduction of a desired fluid, and an externally threaded portion between the ends for engaging the body within the cooperative port. In assembly, the sealing member seals the body to the cooperative port, thereby permitting flow of fluid throughout the orifice and into the cooperative port.
In yet another embodiment, a fixed orifice expansion device includes a body having top and bottom ends, with a bore extending therethrough. Further, the top end has a means to actuate the body into a desired position within a receptacle socket, and the bottom end has a sealing mechanism to fix the body with respect to the receptacle socket.
It is an object of the present invention to provide a fixed orifice device for small capacity (i.e., to about 0.75 to 3.0 tons) refrigerant expansion that may be easily changed. In exemplary embodiments, the device may screw into a standard xc2xcxe2x80x3 valve core compatible ARI flare fitting.
By use of the present invention, a service valve for refrigerant expansion may be made with three standard ARI fittings. Further, any one of the fittings may be used as the expansion port, leaving the remaining ports to act as an inlet (or outlet) and a charging port. By doing so, the number of versions of a basic service valve needed to cover all possible port orientations is reduced.
It is a further object of the present invention to provide an easily changed fixed orifice device for cooling-only systems (as opposed to heat pumps) without the extra expense of requiring a precision check valve/orifice combination.
It is a further object of the present invention to provide an orifice device that screws into a standard ARI fitting (such as a standard xc2xcxe2x80x2 refrigeration fitting) and which advantageously utilizes the taper surface and threads typically used by a valve core. Such an advantage over the prior art permits the device according to the present invention to be universally applicable without a specialized enclosure.
The device according to the present invention may be used in combination with various connectors typically used in the refrigeration industry, such as, for example, flare fittings, such as xc2xcxe2x80x3 and xe2x85x9cxe2x80x3 flare parts and the like.
In operation, the device according to the present invention may be positioned in a receptacle socket of any desired connector. In exemplary embodiments, the device may be screwed into the receptacle socket of the connector, and be sealed into desired position by butting up against a taper in the bottom of the socket. In various embodiments, the seal may be accomplished by an O-ring located about the device, or by a spherical surface machined on the external bottom end of the device. Alternatively, the seal may be molded in place (such as a valve core, as is common in tire and charging port applications) or heat shrunk onto a groove of the device.
In exemplary embodiments, the taper and socket are made to the same dimensions as used for a depression type valve core, which is used in charging ports of almost all air conditioning service valves (and also automotive tires).
As used herein, a xe2x80x9cthreadedxe2x80x9d portion has one or more threads. Additionally, xe2x80x9cthreadxe2x80x9d means any spiral or helical configuration that may be provided on any device for the purpose of facilitating the engagement of parts as discussed below in greater detail. It is understood that such configurations include, but are not limited to, any conventional threads known in the art such as American National pipe threads, Unified threads, SI threads, Acme stub threads, Whitworth threads, any non-conventional (i.e., proprietary) threads, or any multi-pitch threads. As used herein, one xe2x80x9cthreadxe2x80x9d means the extent of the configuration which may be engaged in a single revolution of the device on which the thread is provided, while xe2x80x9cthreadsxe2x80x9d means the extent of the configuration which may be engaged by more than a single revolution of the same, but not necessarily two full revolutions.
As used herein, xe2x80x9cfluid fittingxe2x80x9d means any conventional fluid fitting known in the art, such as a flare, ferrule, rotary (including sweat and weld), or braze fitting, etc., any conventional thread known in the art, such as those mentioned above, any non-conventional thread, or any non-conventional fluid fitting.